Flexible displays bend towards reality

A team of American engineers has developed a process that moves flexible self-illuminated displays a step closer to mass-manufacturing marketability.

Researchers at Arizona State's Flexible Display Center (FDC) have combined a flexible polyethylene naphthalate substrate from DuPont Teijin Films with a PHOLED (phosphorescent organic light-emitting diode or device) display system from the Universal Display Corporation to create a 4.1-inch monochrome 320-by-240-pixel prototype.

Flexible OLED displays have long been thought to be an ideal solution to the challenge of building pocketable devices with large displays. Such a display could, for example, be unrolled from inside a handheld like a window shade or opened like a book, thus providing a viewing area larger than a display simply built onto the surface of the device.

Such displays have proved devilishly difficult to develop, however. The first truly flexible OLED display was demonstrated by Sony back in 2007. The company has continued to refine its technology, demoing an upgraded version as recently as this year's Consumer Electronics Show in January. Japan's NHK has also shown a prototype, as has Samsung.

The problem with flexible OLEDs - as is true with so many leading-edge technologies - has been manufacturability and cost. But since the FDC's process uses a number of standard manufacturing methods, it should have a significant edge in this respect.

According to a press release issued by the FDC and Universal Display, the new technology "achieves the same brightness as traditional displays with extremely low power consumption," two additional factors that point to a promising future in handhelds. Universal Display, in fact, claims that its PHOLED technology can convert "up to 100 percent" of the power fed to it into into light, while old-style fluorescent OLEDs convert only 25 per cent into usable light.

Although the new - and exceptionally flexible - prototype is a monochrome display, the FDC's director of engineering Shawn O’Rourke says: "The fact that we have achieved a functional flexible OLED manufactured directly on plastic using the Center’s manufacturing process represents a significant achievement, and continued developments over the next few years will lead to full color, full motion video flexible displays."

For more information, show up at 11:40 a.m. this Friday at the Society For Information Display's 47th annual Display Week 2009 conference in San Antonio, Texas, when the developers will present their tightly titled research paper, "Active-Matrix PHOLED Displays on Temporary Bonded Polyethylene Naphthalate Substrates with 180°C a-Si:H TFTs".

And while you're in San Antonio, don't miss the Flying Saucer Beer Emporium, which - with over 80 beers on tap - offers just about as much flexibility as a bonded polyethylene naphthalate substrate. ®